Railway-traffic-controlling apparatus



May 1, 192a 1,668,243 L. O. GRQNDAHL RAILWAY TRAFFIC CONYTRCBLLING APPARATUS F leq March 11 1927 K a 5 I8 I 2% 1 20 14 R I2 (I I5 Ill ta ls 1.6 M

I I &T v u u Patented May 1 UNITED STA embodying my TES PATENT OFFICEJ rains ogfenounanL, or PITTSBURGH; rnunsrmmma," i i swrrcn & SIGNAL comma rnuusnvnura.

, I RAILWAY-TRAFFIC*CQNTROLLING nrram'rus.

Applicationflled larcli ll, 1927. Serial 11o..174, 512.

and particularly on to f. the

apparatus point out the novel features thereof in claims. a

In the accompanying drawing, Fig. l is a diagrammatic of apparatus embodying my View illustrating one form invention.

Fig. 2 is a diagrammatic view illustrating a modification of the trackway portion of i the apparatus shown in Fig. 1, and also embodying my invention.

Similar reference characters refer to similarparts in each of the views. v

Referring first to Fig.1, the reference character A designates amagnetizable inductor located in the trackway and-provided with a winding 16. I This winding-is at times supplied with alternating current from a generator G the circuit for winding 16be.- ing controlled by a contact 17 of a relay T,

whichrelay may be controlled in any suit able manner by traffic conditions in advance.

Located on the receiver B having Associated with the first winding 10 is a re-' lay R the normal train is a magnetizable two windings 10 and 11.

circuit for this relay being from a generator G through wire 18,

condenser 23, wire "18, windinglO,

front contact 12 of W! re 19, 20, windrelay R wire ing of relay R and wire 22 to generator G The condenser 23 may be omitted if desired, although the use of this condenser will 1mprove the operation of the apparatus.

The

frequency of the current delivered by gen' erator Gr is preferably different from the frequency of the current deliveredby the trackway generator G any suitable train governing means,

Relay R controls such,

for example, as brake application magnet M.

Magnet M" is provi ded with a circuit which includes a source of current 14 and a front contact 13 of relay B.

When. magnet becomes'de energized, itcauses an automatic application of the train brakes.

The second winding 11 onthereceiver B is provided witha relay R is tuned to rescue circuit which includes a and a condenser 14; "This circuit nce at the frequency 1 of the trackwaygeneratorG". 7 Relay R is normally open, but w hen it is closed it closes Q Owing to the fact that vRelay R gized, abut trackway relay T M ductor may an au xiliarygcircuit for relay R, which circult is from generator Gr through wire 18 condenser 23, wire 18, front contact 15o relay RB wire 21, winding of relay R and P f wire 22 to-generator GK. i y a the circuit for rc lay R? is tuned to resonance at the frequency of generator G, this relay will not beenergized bythe alternating current induced in; winding 11 from generator G flowing in winding 10. will, however, be momentarily energized when the receiver B passes over the by the alternating current i trackway inductor A if winding ylti is. energized. v is H i a The operaton of the apparatus. (shown in Fig. 1, is as follows: Normally relay Ris not if :thisfwinding ,is deenerclosed, so that magnet Mis energized with i the result that this magnet does not cause an application of the brakes. 1 When the receiver B passes over a trackway inductor A, one effect of vthis inductor-wilt be to increase the impedance of winding-10. :lf'res lay R .remains'open', the: increased impedanceof winding 10 will cause the currentin relay 1R to bereduced toxsuchlv'alue that this relay willlopen and cause an automatic application of the brakes.

is closed, the alternating current flowing in winding 16 of theftrackway inductor. will cause relay R to be closed momentarily, thereby closing the auxiliary "circuit for relay R and preventing the lat-L ter relay from opening.

IU-Wlll be seen from the foregoing, that when the trackway relay is open, relay R will he opened when the receiver B passes the inductor A:and willremain open. until the receiver'passes another inductor which is supplied with alternating current, or until suitable resetting apparatus not shown in the drawing is operated.

It is, of course, possible that under some conditions winding 16 on the trackway'inhecome ciosed onitself. The parts are preferably so designed that if this should "occur the effect oftheinductor A on the receiver B will still be such. aswto increase the impedance of windlng lO to a sufficient degree to cause. relay R to open. If it is .difiicult to design the. parts to take careiisofythis condition, the. modification shown in Fig. 2 may be used. Referring to If, however,

this view, the train-carried apparatus may be the same'as in Fig.1, but the trackway apparatus comprises two inductors A and A located one immediately in advance. of the other. InductorA is provided with a winding 16 which "is controlled in the same manner as in Fig. 1, but inductor A is not provided with a winding. When the receiver B passes over the inductor A the impedance of winding 10 will alwaysbe increased .to such value that relay R will open, but a short time interval will occur before the application of the brakes actually begins. Prior to the application of the brakes the receiver B passes over the second inductor A, and if this inductor is energized relay R" will become closed, so that relay R will againclose and will prevent the automatic ap lication of the brakes.

8ther means may be employed for insuring'an automatic application of the. brakes in. the event of winding 16 becoming accidentally closed on itself.

One importantfeature of my invention is the fact that if the trackway relay T is closed, an automatic application of the brakes will be prevented regardless of the speed of the train, and that if the trackway relay T is open, an automatic application will occur regardless of the speed of the 7 train. In other words, apparatus embodymg my invention has no low speed limit.

Although I have herein shown and described only two forms of apparatus embodying my invention, it is understood that various changes and modifications may be made therein within the scope of the appended: claims without departing from the spirit and scope of m invention. 7

Having thus descri (1 my invention, what I claim is r V 1. Railway trafiic governing apparatus comprising a train carried -magnetic receiver having two'windings, a circuit for the first winding including a source of alternating current and a first relay and a front contact of said relay, a trackway inductor to 7 operating with said receiver to reduce the' current in said circuit to such value as to open said first relay, a winding on said inductor, means for at times supplying said inductor winding. with alternatin current, a circuit for the second receiver winding including a second relay responsive to the flux induced in said receiver b alternating current in said inductor winding but not to flux created in the receiver by alternating current in the first receiverrwindin means operating when said second relay is closed for preventing said first relay from being opened 7 due to'the influence of the trackway inductor, and governlng means on the train controlled by saidfirst relay.

Railway traffic governing, apparatus controlled by said first comprising a train carried magnetic receiver having two windings, a circuit for the first winding including a source of alternating current and a first relay andra front contact of said relay, a trackway inductor co-operating with said receiver to reduc'e'the current in said circuit to such value as to open said first relay, awinding on said inductor, means for at times supplying said inductor windin with alternating current of a different requency from that of the source on the train, a circuit forthe second receiver winding tuned to resonance at the frequency of said trackway source and including'a sec ond relay, means operating when said second relay is closed for preventing said first relay from being opened due to the influence of the trackway inductor, andgmcrning means on the train controlled by said firit relay.

3. Railway trafiic governing apparatus comprising-a train carried magnetic receiver having two windings, a circuit for the first winding including a source of alternating current and-afirst relay and a front contact of said relay, atrackway inductor co-operating with said receiver to reduce the current in said circuit to such value as to open said first relay, a windin on said inductor, means for at times suppl ying said inductor winding with alternating current, a circuit for the 'secondreceiver winding including a second relay responsive to the flux induced in said receiver by alternating current-in said inductor windingbut not to fiuxcreated in the receiver by alternating current in the first receiver winding, an auxiliary circuit for said first relay including said train carried source and a front contact of said second relay, and governing means on theitrain relay. 7

4. Railway trafiic controlling apparatus comprising a trackway inductor having a winding, means for at times supplying said winding with alternating current, atraincarried receiver having two windings, a circuit for the first of said receiver windings including a first relay and a source of current and a front contact of said relay, the effect of said 'trackway inductor on'said receiver regardless of whether the inductor is energized or not being to reduce the current in said relay to such value that the relay'will open, a second relay associated with the second receiver winding and arranged to be momentarily energized passes the inductor if the inductor is energized but not if the inductor is de-encrgized, means operatingwhen said second relay is energized to preventopening ofe said first relay due to the co-action of the inductor and the receiver", and governing means on the train controlled by said first relay.

In testimony whereof I'afiix my-signature;

LARS O; GRONDAHL.

when the receiver 

